Friction particle for brake lining

ABSTRACT

A friction particle, useful in applications where cashew nut shell oil friction particles have been used, may be prepared by the reaction at a temperature from about 225 to about 400 degrees Fahrenheit of a non-oxyalkylated resole with resin selected from the group consisting of an oxyalkylated resole, an alkylated resole, an alkylated novolac, an oxyalkylated novolac, and mixtures thereof until it is insoluble, infusible, and does not soften slightly under mechanical force at temperatures below about 400 degrees Fahrenheit, and has substantially no cohesive or bonding strength.

United States Patent Grazen et al.

[ FRICTION PARTICLE FOR BRAKE LINING [75] Inventors: Frank S. Grazen;Melvin L. Buike;

Frank M. Bryzinsky, all of North Tonawanda, NY.

[73] Assignee: Hooker Chemicals & Plastics C0rp., Niagara Falls, NY.

[22] Filed: Dec. 27, 1972 [21] Appl. No.: 319,109

Related US. Application Data [62] Division of Ser. No. 188,598, Oct. 12,1971, Pat. No. 3,781,241, which is a division of Ser. No. 872,753, Oct.30, 1969, Pat. No. 3,658,751.

[52] US. Cl 260/38, 260/19 R, 260/19 A, 260/39 R, 260/39 M, 260/39 SB,260/51.5, 260/838, 260/840, 260/D1G. 39 [51] Int. Cl. C08g 37/18, C08g51/10 [58] Field of Search 260/838, 38, DIG. 39

[56] References Cited UNITED STATES PATENTS 2,985,614 5/1961 Bright260/838 1 1 Mar. 25, 1975 3,207,652 .9/1965 Shannon 260/838 3,410,71811/1968 Smith 260/338 3,658,751 4/1972 Grazen et al. 260/838 3,709,8491/1973 Lemon 260/838 Primary E.raminerJohn C. Bleutge Attorney, Agent,or Firm-Peter F. Casella; James F. Mudd [57] ABSTRACT A frictionparticle, useful in applications where cashew nut shell oil frictionparticles have been used, may be prepared by the reaction at atemperature from about 225 to about 400 degrees Fahrenheit of anon-oxyalkylated resole with resin selected from the group consisting ofan oxyalkylated resole, an alkylated resole, an alkylated novolac, anoxyalkylated novolac, and mixtures thereof until it is insoluble,infusible, and does not soften slightly under mechanical force attemperatures below about 400 degrees Fahrenheit, and has substantiallyno cohesive or bonding strength.

14 Claims, No Drawings FRICTION PARTICLE FORBRAKE LTNING This is adivision of copending application Ser. No. 188,598, filed Oct. 12, 1971,now U.S. Pat. No. 3,781,241 issued Dec. 25, 1973; which is a division ofapplication Ser. No. 872,753, filed Oct. 30, 1969, now U.S. Pat. No.3,658,751.

This invention relates to novel cured phenolic resins to be used as afriction particle material. It is especially useful where cashew nutshell oil friction particles, called Cardolite", have been used in thepast.

Phenol aldehyde, or hydroxy aromatic-aldehyde condensation productshaving methylol side or end groups are known in the art as *resoles".They are formed from condensing a phenol with an excess of aldehyde andwith an alkaline catalyst, also known as onestage" resins and are of thethermosetting type. Except when oxyalkylated, they are self-setting.That is, upon the application of heat there results the formation of aresite, which is an infusible three-dimensional polymer.

Novolac phenol aldehyde resins, on the other hand, are phenolended chainpolymers. They are formed by the reaction of an aldehyde with an excessof phenol in the presence of an acid catalyst and/or heat. They arethermoplastic, permanently soluble and fusible. However, upon theaddition of a curing agent, they can be cured into an insoluble,infusible resin. Thus, novolac resins are known as two-stage resins.

Phenol aldehyde condensation products have been used as binders for;abrasive materials. However, to our knowledge, the novel cured phenolaldehyde products of this invention have not been used as a frictionparticle per se.

As used herein friction particle" is intended to mean having theproperties of substantially no softening at elevated temperatures andwill not flow together or cohere with other particles, as a frictionbinder" would, or fuse with like friction particles. It is insoluble,having an acetone extraction of less than 35 percent and often less than5 percent; it is infusible, i.e., has gone beyond the B" stage, to theC" stage. It will not melt at 700 degrees Fahrenheit. A frictionparticle is held in place with a friction binder.

As used herein, a friction binder" has the properties of ilowability,and has adhesive and cohesive bonding action and thereby binds togetherthe asbestos and other additives (including a friction particle)necessary for building a brake lining or other similar article ofmanufacture. The binder, as supplied to the industry, will melt as a drypowder or is a liquid resin, and can be either an A" stage or B stageresin. The binder becomes a C stage resin after it is combined with theother ingredients and cured.

This composition of the binder. friction particle and other additives,is heated to about 300-400 degrees Fahrenheit and pressed at about500-2000 pounds per square inch in order to form a brake lining-composttion, or clutch facing or other braking device. Thus, the frictionparticle is substantially insoluble and infusible, softening only atelevated temperatures (i.e., above about 400500 degrees Fahrenheit).

It has now been found that a composition of matter useful as a frictionparticle can be prepared by the reaction at a temperature from about 225to about 400 degrees Fahrenheit of a non-oxyalkylated hydroxy aromatichydrocarbon-aldehyde resole with a resin selected from the groupconsisting of an oxyalkylated hydroxy aromatic hydrocarbon-aldehyderesole, an alkylated' hydroxy aromatic hydrocarbon-aldehyde resole, analkylated hydroxy aromatic hydrocarbon-aldehyde novolac, an oxyalkylatedhydroxy aromatic hydrocarhon-aldehyde novolac, and mixtures thereof,until it is insoluble, infusible, and does not soften slightly undermechanical force, such as a spatula at temperatures below about 400degrees Fahrenheit, and has substantially no cohesive or bonding actionor strength. The crude material is initially in lump form, which is thenground to the size specification of the customer. The first said resolecan be alkylated but not oxyalkylated. Among the preferred embodimentsof this invention are the following:

1. The reaction product of between about 5 and about 40 percent byweight of an oxyalkylated resole with between about 95 and about 60percent by weight of one or more of a. one or more non-oxyalkylated,non-alkylated resoles,

b. a non-oxyalkylated, alkylated resole,

c. a mixture of a non-oxyalkylated alkylated resole and anon-oxyalkylated, non-alkylated resole,

d. a mixture of a non-oxyalkylated, non-alkylated resole and anon-oxyalkylated alkylated novolac, and

e. a mixture of a non-oxyalkylated. non-alkylated novolac and anon-oxyalkylated. non-alkylated resole.

2. The reaction product of between about 95 and about 60 percent byweight ofa non-oxyalkylated, nonalkylated resole with between about 5and about 40 percent by weight of one or more of a. an oxyalkylatednovolac, and

b. a non-oxyalkylated, alkylated resole.

3. The reaction product of between about 5 and about 40 percent byweight of an oxyalkylated novolac with between about 95 and about 60percent by weight of one or more of a. two or more non-oxyalkylated,non-alkylated resoles,

b. an alkylated resole,

c. a mixture of an alkylated resole and a nonoxyalkylated, non-alkylatedresole,

d. a mixture of a non-oxyalkylated, non-alkylated resole and anon-oxyalkylated alkylated novolac. and

e. a mixture of a non-oxyalkylated. non-alkylated re- .sole and anon-oxyalkylated, non-alkylated novolac.

4. The reaction product of between about 5 and about 95 percent byweight of a solid. B-stage nonoxyalkylated, alkylated resole. withbetween about 95 and about 5 percent by weight of a liquid, A-stage,nonoxyalkylated, alkylated resole.

5. The reaction product of between about and about percent by weight ofa nomoxyaikylated. alkylated resole, with between about 30 and about 10percent by weight of a non oxyalkylated. alkylated novolac.

6. The reaction product of between about 5 and about 50 percent byweight of a non-oxyalkylated, alkylated resole. with between about 5 andabout 30 percent by weight of a non-oxyalkylated. alkylated novosole arebelieved to be needed to react with the polyol groups of theoxyalkylated materials.

The friction particle is formed by blending and react ing the resolewith the novolac, or oxyalkylated resole. Usually, the resole andoxyalkylated resole or oxyalkylated novolac are both liquids. soblending is easily achieved. However, when one is a solid, it ispowdered and mixed with the liquid. When both are solids, both are dryblended such as by ball milling together. Then they are mechanicallyblended, such as by being passed through a hammer mill equipped with aquarter mesh screen.

Following blending, the resins are heated to about 225 degreesFahrenheit to about 400 degrees Fahrenheit, and preferably from about325 degrees Fahrenheit to about 375 degrees Fahrenheit, until a resin offriction particle consistency is formed.

Examples of phenols which can be used in preparing a phenol aldehyderesole or novolac for use in practicing the invention include ortho-,paradirecting hydroxy or amino aromatic compounds having 6 to 24 carbonatoms such as phenol itslef (C H OH), naphthol, anthranol andsubstituted derivatives thereof where the substitutents on the aromaticcompound are independently selected from H. Cl, Br, F, NH and 21. alkylgroups or radicals of l to 60 carbon atoms, preferably of l to 30 carbonatoms, and their various isomeric forms and substituted on the aromaticnucleus in the ortho or para position;

b. cycloalkyl groups of to l2 carbon atoms such as cyclohexyl,cyclopentyl, methylcyclohexyl, butylcyclohexyl, and so forth;

is. alkyl, aryl and cycloalkyl ketonic groups wherein the hydrocarbonportion is as defined above in (a) and (1. alkyl, aryl and cycloalkylcarboxylic groups wherein the hydrocarbon part is defined as above in(a) and (b);

e. aryl groups of 6 to 24 carbon atoms such as phenyl, naphthyl,anthryl, and the like;

f. aryl substituted alkyl wherein the aryl is phenyl which may containlower alkyl and/or hydroxy substituents so that the resulting hydroxyaromatic is, for exampie, :1 bisphenol; and

g. mixtures of the aforesaid hydroxy aromatics.

Suitable substituted phenols include the following: para-phenyl phenol,para-benzyl phenol, para-betanaphthyl phenol, cetyl phenol,para-cumyl-phenol, para-tert-butyl phenol, sec-butyl phenol,para-tertamyl phenol, para-tert-hexyl phenol, para-alphanaphthyl phenol,para-hydroxyacetophenone, parahydroxybenzophenone, para-isoctyl phenol,para-tertoctyl phenol, para-cyclohexyl phenol, para-d-limonene phenol,para-l-limonene phenol, a phenol alkylated with oleic acid, such asphenol alkylated with oleic acid, para-decyl phenol, para-dodecylphenol, paratert-decyl phenol, butyl naphthol, amyl anthranol,para-nonyl phenol, para-methyl phenol, bisphenols such aspara,para'-isopropylidene diphenol, para,para'- methylene diphenol, aswell as the corresponding orthoderivatives of the previously mentionedcompounds such as ortho-butyl phenol and ortho-nonyl phenol as well asmixtures thereof, and aniline.

Mixtures of various hydroxy aromatic compounds mentioned herein also maybe used.

lncluded among the phenolic reactants which may be used are those knownas the cresylic acids" and these often comprise a heterogeneousmixtureof having two reacting hydrogen positions on each of them; thatis, compounds unsubstituted in the orthoand parapositions of themolecule, to compounds that only have one functional position, andhence, relatively unreactive. These compounds may include the following:3,5- xylenol. m-cresol, 3,4-xylenol, 2,5-xylenol, 2,3-xylenol, phenol,p-cresol, orthocresol, 2,4-xylcnol, and 2,6- xylenol. Cresylic acids ortar acids are generally applied to phenol and its homologs which mayinclude cresois, xylenols, trimethyl phenols, ethyl phenols, and higherboiling materials such as dihydroxy phenols, polycylic phenols and thelike. They are often obtained by a lowtemperature trimerization of coal,lignite, and the like, or a conventional high-temperature coke oven tar,or the liquid product of petroleum cracking both thermo and catalytic,shell oil, coal hydric hydrogenation products, and the like.

Polyhydroxy aromatic reactants, such as resorcinol, may also be used.

Particularly useful in this invention are mixtures of aniline and phenolto react with an aldehyde or ketone to produce either a novolac or aresole, depending on the other conditions described above.

Also useful in the invention are mixtures of urea and phenol to reactwith the aldehyde or ketone to produce either a novolac or a resoledepending on the other conditions described above.

Among the aldehydes which may be used within the scope of this inventionto produce either the resole or the novolac, are formaldehyde or any ofits variations, such as 37 percent formalin concentration orparaaldehyde, acetaldehyde, propionaldehyde, isobutyraldehyde,isopentaldehyde, and the like. The aldehyde should have not more than 8carbon atoms and should not detrimentally affect the resinification oroxyalkylation of the resin. Preferred aldehydes are those having from 1to 4 carbon atoms, suchas formaldehyde, which may be in aqueous solution(37 percent), or in any of its low polymeric forms such as paraform ortrioxane. Other aldehydes include para-aldehydes, furfural. 2-ethyl-hexanal, ethylbutyraldehyde, heptaldyde and glyoxal, benzaldehydeand crotonaldehyde.

Nova LAcs To prepare a novolac, the proportion of aldehyde to becondensed with theihydroxy aromatic compound may be varied in order toobtain different molecular weights, and the viscosity of the finishedresin may be controlled by the mole weight of the novolac; preferablythe proportion of aldehyde employed is from 0.5 to L0 per mole of thehydroxy aromatic compound.

Among the substituted phenols which may be used to prepare the novolacsfor this invention are those substituted with long-chain ethyleneicallyunsaturated hydrocarbons, such as the linseed-type oils. However, it iswithin thescope of this invention to employ an animal and/or vegetableoil which achieves the objects of this invention based on the similarityin properties with the long-chain hydrocarbon oils. Such oils would bepositioned on the phenol in the orthoor p arapositions, and preferablyin the paraposition. Many of them are similar in properties to linseedoil having nonconjugated unsaturation of at least 50 iodine number, andhave sufficient compatibility with the novolac after it is polymerized.Sa'fflower oil is typical of these oils. It'may be in the form of aglycerol ester of the fatty acids wherein the fatty acids are of acomposition comprising more than 40 percent by weight of linolenic acid.The remaining percentages of fatty acid can be any saturated orethylenically unsaturated fatty acid having l2 to 22 carbon atomsandmore preferably oleic and linolenic acid so that the fatty estershave an iodine number of at least 50. The iodine value (iodine number)is a measure of unsaturation, and is defined as the number of grams ofiodine required per 100 grams of unsaturated material to obtain thesaturated material. In addition to the preferred glycerol ester, otherpolyhydric alcohols can be reacted with the described fatty acids toproduce a low acid number ester of a polyol having 2 or more hydroxylgroups. Typical polyols include ethylene glycol, diethylene glycol,pentaerythritol, dipentaerythritol, sorbitol and the other polyhydricalcohols.

The acid catalyst to be used when preparing the novolacs to be used inthis invention may be chosen from oxalic acid, sulfuric acid,hydrochloric acid and other strong acids used in the art for preparingnovolacs. In addition, wetting agents of the anionic type, such assodium alkylaryl sulfonates, are also useful as secondary catalysts inpreparing novolacs.

The two-stage resins are curable by reaction with hexamethylenetetramine to form dibenzyl and tribenzyl amines, as well ashexatriphenol. One may also use ammonium hydroxide, which reacts withthe formaldehyde to form hexamethylene tetramine. Other amines may alsobe used, such as ethylene diamine or ethylene triamine, or methylamines,etc. These can be used to react with formaldehyde to'form a compositionsimilar to hexamethylene tetramine. The resulting compound would be analdehyde donor.

The phenol aldehyde novolac type resin is prepared by charging thedesired phenol and aldehyde raw materials and catalysts to a reactionvessel. The reaction begins at about 100 degrees centigrade and proceedsunder temperatures up to about 200 degrees centigrade, at any pressureup to about 100 lbs/square inch gauge for about one and one-half hours,or until the desired degree of polymerization has taken place.Thereafter, the catalyst is neutralized where necessary, and the excessreactant, water, and other materials and taken off by dehydration andthe moltenresin is discharged from the vessel. It has been found that anovolac which has not been neutralized and is stable will cure morerapidly with a resole than a novolac which has been neutralized.

From the foregoing, it is apparent that many hydroxy aromatic compoundsmay be used in practicing the present invention to provide a novolacwhich can be then reacted with an hydroxy aromatic aldehyde resole toform the friction particle of this invention, provided the aromatichydroxyl group is reactive and the hydroxy aromatic compound is capableof reacting with an aldehyde or a mixture of aldehydes to produce anovolac condensate. Pure, refined phenols may be used, but this is notnecessary. For instance, phenols may be alkylated and then may bereacted in crude form with under a vacuum of between about 20 and about30 inches of mercury. Then, the dehydrated phenolic material isacidified to a pH of between about 1 and about 5 with H 80, or in somecases BF Following this, a terpene or vegetable oil is added and thereaction mixture heated to between about 80 and about 140 degreescentigrade at atmospheric pressure. The molar ratio of reactants isbetween about 0.1 mole of terpene or vegetable oil per mole of phenol toabout 2.5 mole of terpene or vegetable oil per mole of phenol. When tungoil is employed as a vegetable oil in the alkylation, use of BF;, toacidify would cause gelation, so it is not used, but H 80, can be used.

The proportion of aldehyde to be condensed with the hydroxy aromaticcompound to form a precondensate may be varied to prepare novolacs ofdifferent molecular weights. Viscosity of the finished precondensate maybe controlled by the mole weight of the novolac. Preferably, theproportion of aldehyde employed varies from about 0.5 to 1.0 mole permole of phenol when a monoor difunctional phenol is used. in instanceswhere a trifunctional phenol is used, i.e., unsubstituted in theorthoand parapositions, a preferred upper limit of the aldehyde may beabout 0.70 mole of aldehyde per mole of phenol so as to minimize theformation of insoluble, infusible condensates. it is preferred that thealdehyde and phenol be condensed using an acid catalyst to shorten thetime required for complete condensation of the reactants. Suitable acidcatalysts include sulfuric acid, hydrochloric acid, and oxalic acid.These catalysts are generally employed in the amount of 0.1 to about 5percent by weight of phenol to be condensed. I

Where a mixed aldehyde, phenol-aldehyde preconthe desired phenol andaldehyde raw materials and catalysts to a reaction vessel. Thereactionproceeds under an aldehyde. in such crude form, the phenols maycontemperatures from about 25 to about 150 degrees centigrade at apressure from about ambient up to about 100 pounds per square inch gaugepressure for a period of time from about 5 minutes to aboutS hours, asuitable timebeing about. one and one-half hours, or until the desireddegree of condensation has taken place. The'phenol is first reacted withthe longer-chain aldehyde to form a phenol-longer chain aldehydeprecondensate, followed by a second-step reaction of the phenol-longerchain aldehyde precondensate with formaldehyde to form a thermosettablephenol aldehyde precondensate material. In the second step, thereactants are refluxed at atmospheric pressure, although higher refluxtemperatures up to about 150 degrees centigrade can be used by employingelevated pressure. The formaldehyde can be added all at once in thesecond step, or added gradually. If the formaldehyde is added all atonce, then a temperature range between about 50 and about 60 degreescentigrade is used at the beginning of the second-step reaction, untilthe exothermic reaction subsides, and then the temperature is increasedslowly to between about and about degrees centigrade and held untilfurther exothermic reaction subsides, and then the reaction mixture isheated to reflux temperature which is about degrees centigrade atatmospheric pressure. If elevated pressure is used, then the refluxtemperature can be increased to as high as about degrees centigrade. ifthe formaldehyde is added gradually in the second step, then atemperature range between about 95 and about l40 degrees centigrade canbe used. The catalyst is then neutralized and the excess reactant, waterand other materials are taken off.-

While the precondensate is still at an elevated tern perature, fromabout 25 degrees to about 150 degrees centigrade, but below the boilingpoint of the resultant solution or supension, with about 100 degreescentigrade being very suitable, it may be reduced in viscosity byaddition of suitable solvent. The amount of solvent may vary from about10 to 70 percent of the precondensate by weight and a suitable ratio ofprecondensate to solvent is about 10 parts of precondensate to 9 partsof solvent. The controlling factor is the resulting viscosity of theprecondensate prepared, rather than the actual volume of solventcharged. Among the solvents which may be used for this purpose areethanol, methanol, toluene, xylene, ketones, such as acetone, andmethylethyl ketone, and mixtures of aromatic and aliphatic hydrocarbons,such as mixtures of benzene and mineral spirits, or benzene and acetone.

OXYALKYLATION Oxyalkylated resins are prepared which preferably containsubstantially no free reactive hydroxy aromatic groups, for example,less than about 0.5 percent of the aromatic hydroxyl present originallyin the hydroxy aromatic or hydroxy aromatic aldehyde condensate. Toremove the aromatic hydroxys, the hydroxy aromatic aldehyde resin can bereacted with a compound which etherifies the aromatic hydroxyl groups sothat almost all of the aromatic hydroxy groups present in each hydroxyaromatic aldehyde condensate unit are so reacted.

The preferred method of hydroxyalkylation is by reaction with compoundscontaining a mono-oxirane ring. Such compounds include ethylene oxide,propylene oxide, butylene oxide, styrene oxide and cyclohexene oxide,glycidol and ephichlorohydrin. Many other monoepoxides can be used, butthe alkylene oxides containing not more than 6 carbons are generallypreferred. Additional useful compounds are phenyl glycidyl ether andrelated compounds prepared from the reaction of epichlorohydrin andmonofunctional alkylatcd and halogenated phenols such aspentachlorophenyl glycidyl ether.

Catalysts for the reaction of the oxirane ring compounds and phenolichydroxyl groups may be alkali or alkaline earth hydroxides, primaryamines, secondary amines, tertiary amines or basic alkali salts. Theseinclude sodium, potassium, lithium, calcium and barium hydroxides,amines such as methyl, dimethyl, diethyl, trimethyl, triethyl,tripropyl, dimethyl benzyl, dimethyl hydroxyethyl,dimethyl-2-hydroxypropyl and the like, and salts ofstrong bases and weakacids such as sodium acetate and benzoate.

The reaction may be carried out at temperatures of about roomtemperature to 250 degrees centigrade,

and preferably in'the absence of solvents, although sol-- vents may beused to reduce viscosity when desired. When oxyalkylating resoles, thereaction should be carried out at lower temperatures than whenoxyalkylating novolacs, because there is a possibility that reaction ofthe methylol groups with other methylol groups gives methylene linkages,formaldehyde and gelation. When oxyalkylating a novolac, temperaturesbetween room temperature and about 200 degrees centigrade can be used.When oxyalkylating a resole, temperatures between room temperature andabout 100 degrees centigrade may be used.

The aromatic hydroxyl of the novolacs may also be hydroxyalkylated byreacting alkylene halo'hydrins with the aromatic hydroxyl usingequivalent amounts of an alkali metal hydroxide to bring about thereaction. Suitable alkylene halohydrins are ethylene chloroandbromohydrins, propylene chloroand bromohydrins. 2,3- butylene chloroandbromohydrins. and glyceryl chloroand bromohydrins.

Another method for hydroxyalkylating novolacs is reaction with alkylenecarbonates such as ethylene carbonate and propylene carbonate. using acatalyst such as potassium carbonate.

At least one mole of alkylene oxide or other etherifying or esterifyingagent is required per mole of aromatic hydroxyl. However, resinsprepared by reaction with up to 7 moles of alkylene oxides per mole ofphenolic hydroxyl have been found to be useful.

RESOLES critical in this process. Less than 2 percent free CH O isdesirable. The reaction mixture is then cooled and the catalystneutralized with some acid such as glacial acetic acid and the pH isadjusted to roughly 6 to 7.5. The reaction mixture may be then furtherreacted with hexamethylene tetramine or some other aldehyde donor, i.e.,curing agent. The resinis then dehydrated to between about 50 to 95percent solids, and preferably between about 81 to 85 percent solids.

The alkaline catalyst used in preparing the resoles to be used in thisinvention may be any of those known in the art; for instance, sodiumhydroxide and calcium hydroxide. In general, the alkali metal hydroxidesand the alkaline earth metal hydroxides and ammonium hydroxide and theamines such as triethanol amines may be used.

Following the intercondensation reaction to form a resole, astoichiometric quantity'of a strong acid such as sulfuric acid,hydrochloric acid. phosphoric acid or oxalic acid. or the like, is addedto the reaction mixture in order to neutralize the alkaline condensationcatalyst. Sulfuric acid is conveniently employed to neutralize a sodiumhydroxide catalyst. The alkaline catalyst may also be neutralized bydilution through repeated washing, however, it is preferred to use anacid. The final resin should have a pH between about 5.5 and 7.5 forgood stability.

The hydroxy aromatic compound employed in a resole can be alkylated, ifdesired, with alkyl groups containing l to 12 carbon atoms, or withunsaturated groups, including the long-chain unsaturated vegetable oranimal oils, to form alkylated hydroxy aromatic compounds that whenreacted with an aldehyde form heat reactive resoles. These includealkylene groups of 2 to 36 carbon atoms, fatty acids, polyethers, alkylethers, polyesters and polyols and mixtures of these.

Among the high molecular weight or polymeric materials containingaliphatic carbon-to-carbon unsaturation, there are included suchnaturally occurring materials as unsaturated vegetable, flsh or animaloils such as linseed, soya, tung, sesame, sunflower, cotton seed,herring, menhaden, and sardine oils, etc., or chemically modifiednaturally occurring materials such as allyl ethers of starch, celluloseor acrylate esters thereof, etc., synthetic drying oils, polymersobtained by polyctherification of such unsaturated compounds such asmaleic, fumaric. itaconic, aconitie, chloromaleic, dimerized fattyacids, anhydrides or acids from allyl glycerol, methallyl glycerolether, glycerol monoacrylate, butene diol, pentene diol, or polymersobtained by polyetherification of the unsaturated polyols. Other oilsinclude castor oil, tall oil, oiticica oil, safflower oil, and the like,oleic and linolenic acids. These fatty acids have from 12 to 22 carbonsatoms. They are often in combination as a glycerol ester or incombination with other polyhydric alcohols or polyols such as ethyleneglycol, diethylene glycol, pentaerythritol, dipentaerythritol, sorbitol,and the like polyhydric alcohols.

The blending and reacting of the resole with the other components inaccordance with this invention may be in various proportions, dependingupon the ultimate properties desired in the friction particle to beproduced, but will generally be in the range of about 60 to about 95weight percent of the non-Oxyalkylated resole based on the total weightof resin components.

It is to be understood that the Oxyalkylated resole or oxyalkylatednovolac described herein will not be a friction particle alone unlessreacted with a nonoxyalkylated, non-alkylated resole resin or with anonoxyalkylated, alkylatcd resole resin. The Oxyalkylated resole productis a liquid and will not cure. The preferred compositions of theinvention contain at least one of an oxyalkylated resole and anOxyalkylated novolac in com bination'with the non-Oxyalkylated resole.

The friction particle of this invention may be used alone or with otherfriction materials known in the art. A typical friction element containsabout 30 to 60 weight percent asbestos fiber, up to 40 weight percentother inorganic filler and abrasives, about to weight percent organicfiller, including the particle ofthis invention, and about 15 to 30weight percent binder; all percents are by weight of total composition.Asbestos fiber, other abrasive materials and filler materials arecharged into a mixer followed by the addition of a binder, such as avarnish material. The materials are kneaded until the fiber, abrasives,and any fillers are thoroughly wetted and a uniform mass is obtained.The mass is discharged from the mixer, rolled out into sheets orextruded or pressure molded and dried, after which it is ready forfurther processing into friction elements.

The abrasives, that is, the friction imparting agents and fillers, whichmay be used in addition to the abrasive material disclosed and claimedherein, within the scope of this invention include, but are not limitedto brass chips, metal shavings and filings, silica, talc, wood flour,chalk, clay, mica, fiber glass, felt, carbon black, graphite, metalnitrides and oxides, and ground cashew nut shell oil polymerizate. Theseabrasives and fillers may be used in addition to the friction particleof this invention to achieve the particular amount of bulk andcoefficient of friction desired. Some consumer specifications specifythat the friction particle should be 90 percent finer than mesh andcoarser than 100 mesh. Other consumer specifications call for coarser orfiner friction particles.

The following examples are given to further illustrate 5 the invention.Unless otherwise indicated, all parts are by weight and temperatures indegrees Centigrade.

EXAMPLE 1 PART A (The Resole) A reaction vessel is charged with 100parts of phenol, 5 parts of cresylic acid, ll0 parts of formalin (37percent formaldehyde) and L0 part of flake caustic dissolved in 4 partsof water. This reaction mixture is heated gradually to reflux and heldat reflux to less than 5 percent free formaldehyde and cooled to 70degrees Centigrade, after which 1.5 parts of glacial acetic acid isadded which neutralizes this composition to a pH of 6.8-7.2. After thepH range is achieved the resin is dehydrated to 81-85 percent solids andcooled to room 20 temperature. The resultant product is a viscousliquid,

and is identified as resin Ra in Table V.

PART B (The Oxyalkylated Novolac) For this Example, a resin was usedwith a ratio of 2 moles of ethylene oxide to one mole of phenol.

A typical modified phenol-aldehyde condensation product is prepared byintroducing 3,000 parts phenol, 13 parts of oxalic acid catalyst and 6parts of a wetting agent of Nacconol (sodium alkylaryl sulfonate) into ajacketed reactor and heating to 100 degrees centigrade. (The anionicwetting agents of alkylaryl sulfonate type are preferred.) Then l,l 10parts ofa 37 percent aqueous formaldehyde solution are added to thereactor at a rate that the heat of reaction provides a vigorous reflux.Refluxing is continued for 2 hours after the completion of the formalinaddition. The reactor contents are dehydrated at 180 degrees centigradeand then dephenolated at 200 degrees centigrade at 50 millimetersvacuum. Approximately 2,030 parts of phenolaldehyde condensate areproduced. Then 7.2 parts of sodium hydroxide are introduced to thereactor. Ethylene oxide is then added to the reactor aseither a vapor ora liquid. The reactor temperature is maintained at 190 degreescentigrade for the initial 2 hours and is then permitted to increase tothe range of 200 to 220 degrees centigrade until the addition of 878parts of ethylene oxide is complete. The resulting condensation producthad a hydroxyl number of 370, and a Gardner viscosity at.5() degreescentigrade of about 2,000 seconds, and is resin Nf in Table VI.

The novel friction particle is made by blending 60 parts of Part A with40 parts of Part B, curing 8-16 hours at 325 to 375 degrees Fahrenheit,grinding to the desired screen size necessary for a friction particleuseful in the arts. In this particular Example, the blend was cured for16 hours at 350 degrees Fahrenheit and ground to 20 mesh. The resultingparticle was made up into a brake lining, tested by standard proceduresand found to be satisfactory for this use.

EXAMPLE 2 70 parts of Part A and parts of Part B of Example 1 wereblended and reacted, using the same curing cycle as in Example 1. Theresulting product was ground to mesh and found to be superior to apolymerized cashew nut shell oil friction particle-known as Cardolite inthe trade. having softening properties at 500 degrees Fahrenheit whencompressed slightly with an 8 inch spatula inch wide by 4 inches long X1/32 inch thick blade). Also the heat loss at 700 degrees Fahrenheit waslower than that of Cardolite.

EXAMPLE 3 80 parts of Part A and 20 parts of Part B of Example 1 wereblended and reacted, using the same curing cycle as in Example 1. Theresulting product was ground to 20 mesh and had properties similar tothose of the product of Example 2.

The particles obtained in the above Examples 1, 2 and 3 were superior tofriction particles made from polymerized cashew nut shell oil commonlycalled Cardolite." presently used as friction particles in thebrakelining industry. The particles made in accordance with theinvention are less subject to migration of components which results inbrake linings with better fade" characteristics. The particles of theinvention are most heat resistant and can be made with more uniformquality. with better control of end properties. The particles are lesstoxic to the skin than Cardolite. which has the further disadvantage ofbeing solely available from foreign sources. The products of theinvention can also be made at lower cost.

EXAMPLE 4 The friction particle (7 parts) of Example 1 was used informulating a mixture comprising 62.37 parts of Dry Mix, 063 part ofhexamethylenetetramine, 16.4 parts of varnish. 20 parts of rubbersolvent (mainly mineral spirits) and 0.6 part water. The Dry Mix'iscomposed of 93 parts by weight of asbestos shorts, Quebec StandardAsbestos Grade 7K, and 7 parts by weight of the friction particles. Themoisture content of the Dry Mix is held low between 0.75 and 1.0 percentto avoid any possibility of blistering of the element during cure.

Toan internal mixer equipped with a Sigma-type blade were charged theDry Mix and hexamethylenetetramine. The dry materials were mixed andblended for 5 minutes. Then the varnish and toluene were added and mixedfor l hour until the mass was uniform. The dough-like mix was thendischarged from the mixer and charged to an extruder. The extruder isequipped with a 2 inch by A inch rectangular die and has an applied rampressure of l()() to 300 pounds per square inch. The dough-like mix wasthen extruded in a shape which was satisfactory for brake linings. Theextruded linings were oven dried for 3 hours and with a gradual increaseof temperature up to about 88 degrees centigrade to remove solvents andother volatiles. The linings were then cut to proper length, reheatedfor 2 to 3 minutes at about 163 degrees centigrade. bent or arched tothe desired curvature and placed into forms (i.e.. molds) for curing.These linings were then cured for 8 hours at about 205 degreescentigrade. The cured linings after cooling were expanded to the propersize for mounting into brake shoes. The resulting friction elements werefound to be satisfactory for use on automobile brakes.

EXAMPLES 5-12 in Table [,Examples 5-12 are shown in tabular form.

in each of these Examples, (except Examples 10. ll and 12) the resinswere weighed into a beaker and mechanically mixed. The mix was spreadinto. aluminum pans (2 V. inches by 7 inches) and cured in anaircirculating oven at the specified temperatureand time. Theformulations for the resoles and novolacs used are given in Tables V andVi, respectively. Example I0 is a repeat of Example 2. in Example I l. aCardolite NC-l04-20 sample of cashew nut shell oil friction particles isgiven for comparison purposes. in Example 12. since both resins areliquids. the materials were mixed in a 15 gallon kettle. in all otherrespects. however. the procedures and equipment were the same as theother Examples inTable i.

TABLE I Example Weight Cure Cure Volatile Acetone Hot Plate Behavior atNumber Resole Novolac Ratio Temp. Time Loss Extractable 500F SpatulaTest Resin Resin Resole/ Wt. Formula Wt. Formula Novalac C Hrs. '71 /1 5I95 Rc l5 Na 90/!0 I75 16 M93 2.07 Smoky. softens slightly under s atulapressure I 6" I95 Rc l5 Na 90/10 175 l6 l4.3 3.14 moky. softens slightlyunder spatula pressure 7 225 Rt l5 Na 90/l0 175 I6 22.7 l3.66 ery smoky.softens slightly. color change s 162 Re Nd vo/so T75 l6 l3.(: 25.61Smoky. changes it a wet. oily mess so t 9 225 Rf l5 Nd JO/l0 I75 16 17.9ll.52 Smoky. softens slighth' I0 I40 Ra Ni /30 I20 lb 24.9 21.65 Smoky.very slight softening.

color change I l Cardohte NC-l04-20 Cashew Nut Shell Oil FrictionParticles 25.9 2.59 Very smoky. softens sll l'llh'.

oily odor. particle breti down 12 I40 Rg o0 Nt 70/30 I20 22 l7.27 1.63Smoky. slight softening. color 2.4 grams of hexamethylene tetramine werealso added into the mix. Notes:

Weights are in grams Volatile loss is at 700F for one hour Acetoneextractable test in ASTM D-4Q4-46 All materials tested were groundthrough 20 mesh Ratio is of resin solid content change The resultspresented in Table I indicate that the a commercial Cardolite frictionparticle has a high volatile loss when heated at 700 degrees Fahrenheitfor one hour, a low acetone extractable content and deterio- 14 form.The procedure used is set forth in the footnote of Table 11. Theformulations for the resoles and novolacs used are given in Tables V and'Vl,'respectively.

rated when heated to 500 degrees Fahrenheit on a hot f h EXAMPLES 28-46plate. By contrast, the products 0 t e invention were more stable atelevated temperatures. The results also 1 T bl [1], E l 2846 are shownin tabular exhibit the Control Over Properties that is Possible withform. They are presented to illustrate the variation in compositions ofthe invention. Thus, a low acetone exresults obtain-awe f Example 12 i di E tractable content indicates a hard material, a high acepies 28-41and Example 14 (varied in Examples tone extractable content indicates asofter material. 4246), Th thi invention provides a means of producingfriction particles of variable properties, thereby EXAMPLES 15-27permitting more flexibility in the supply of friction parln Table 11,Examples 15-27 are shown in tabular ticle products to the industry.

ABLE Example Resale Novolac Ratio Volatile Acetone Hot Plate Behavior atNumber Formulation Formulation Resole/Novolac Loss. 7: Extractable.%500F Spatula Test 15 Rg 7.51 A 0.0 No smoking or softening- 16 Ra 6.290.0 No smoking or softening 17 Re Nt 70/30 36.72 2.29 Slightsoftening-slight smoking 18 Re & Rd Nf 70/30 25.92 3.70 Slightsoftening-no smoking 19 Rg Ng 70/30 8.17 0.03 No smoking or softening 20Ra N 70/30 10.23 1.68 Slight softening 21 Rg N 80/20 7.23 0.0 Slightsoftening 22 Ra Nh 80/20 7.00 0.18 Slight softening 23 Rg Ne 70/30 6.600.67 Slight smoking. no softening 24 Re l-lycar 1561 90/10 9.35 0.49Very smoky. melts and turns Rubber Latex 25 Rb & Rc Nf /30 18.35 0.58 Nosmoking. no softening 26 Rg Nc /20 7.0 4.34 Slight smoking. slightsoftening 27 Ra Nc 70/30 6.45 0.60 Slight smoking, no softening Notes:

All components were weighed into a beaker (200 grams total mix) andmechanically mixed. The mix was spread into aluminum pans (211" X 7")and cured in an air circulation oven at 175C for 16 hours.

Acetone extractable test is ASTM D-494-46 Volatile loss is at 700F forone hour All materials tested were ground through 20 mesh TABLE 111VARIATIONS ON EXAMPLES 12 AND 14 IN TABLE 1 Example Rcsole Novolac CureCure Volatile Acetone Number For- Formul- Ratio- Time Temp Lossf/zExtract- Comments mullntion lation Hours "C able. '7:

28 Rat Nf 70/30 1 200 9.4 23.58 Mixed under vacuum while heating from Cto C Hot plate cure 59 sec.

29 Ra Nf 70/30 16 21.4 28.59 Mixed under vacuum while heating from 85Cto 105C. Hot plate cure 72/77 sec.

30 Ra Nf 60/40 16 120 16.96 41.8 Mixed under vacuum while heating from85C to 90C. Hot plate cure 101/106 sec.

31 Ra Nt 70/30 16 120 14.0 24.5 Mixed under vacuum while heating from115C to 105C. Hot plate cure 46/51-see.

32 Ra Nf 70/30 2 200 14.2 32.63 Resins physically mixed 33 Ra Nf 70/30 519.7-21.8 17.5-22.4 Hot plate cure 55/60 sec.

34 Ra Nf 70/30 4 180 l2.5-l5.0 22.2-23.8

35 Ra Nf 70/30 0.1 440 23.5-25.1 81.65-12.33 Resins physically mixed 36*Ra Nf 70/30 0.05 440 27.4 15.67 Resins physically more 37 Ru N1 70/30 5min. 600F 23.6 19.45 Resins physically mixed 38 Ra N1 70/30 6 min. 600F24.8 17.76 Resins physically mixed 39 Ra Nf 70/30 7 min. 600F 25.1 17.47Resins physically mixed 40 Ra Nf 70/30 8 min 600F 24.4 15.62 Resinsphysically mixed 41 Ra Nf 70/30 10 min. 600F 24.0 15.09 Resinsphysically mixed 42 Rg N1 70/30 3 min. 600F 22.5 5.45 Resins physicallymixed 43 Rg N1 70/30 2 min. 600F 23.3 10.34 Resins physically mixed 44Rg Nf 70/30 4 min. 600F 22.0 7.61 Resins physically mixed 45 R3 Nf 70/305 min. 600F 21.6 7.02 Resins physically mixed 46 Rg Nf 70/30 8 mm. 600F21.9 4.81 Resins physically mixed ,Experiments 28-35 were tested forvolatile loss at 600F for 2 hours and acetone extractable for 16 hours(AS'lM 13-494-46) Experiments 36-46 were tested for volatile loss at7110F for 1 hour and acetone extractable for 4 hours (ASTM D-494-46)EXAM PLES 47-62 In Table IV, Examples 47-62 are shown in tabular form.They are presented to further illustrate the variation in resoles andnovolacs which can be employed to produce a friction particle. Theprocedure used was the same as that in Examples 9 of Table 1.

TABLE IV Oxalkylated Percent Percent Example Resole Novolac ResinVolatile Acetone Hot Plate Behavior Number Formulation FormulationFormulation Ratio Loss Extractable At 500F 47 Rg Rj 70/30 21.19 15.83Slifght smoke-very slight so tening 48 Rf Rj 70/30 31.71 0.11 Smokysoftens odor oily appearance slight caking 49 Rg & Rf Rj /35/30 26.2831.47 Smoky slight softenin odor 50 Rg & Rh R 35/35/30 22.77 24.05Slight smoke slight so teningslight odor 51 kg Nd Rj 15/15/70 14.4315.24 SnLoky Softens, oily ca es 52 Rg Nb Rj 70/15/15 1 1.57 0.89 Veryslight smoke very slight softening 53 R 84 Rf /40 10.51 0.97 No smo every slight softening 54 RF Nf 80/20 20.13 32.99 Smoky slight softeningodor oily 55 Rg & Rf Nt' 40/40/20 16.51 6.59 Slight smoke slightsoftening 56 Rg & Rh Nt 35/35/30 17.88 13.50 Slifght smoke very slightso tening 57 Rg Nd Nf /10/20 13.67 7.30 Slight smoke softens very oi ycakes 58 R Nb Nf 70/10/20 12.26 0.32 No smoke slight softening 59 Rft Ri60/40 10.92 15.96 Slight smoke softens 1 slightly oil sli ht caking 60Rf Nd /20 12.56 18.58 Slight smo e s ight softening slightly oily 61 Rf& Rg Nd 20/70/10 9.18 7.01 Snl1(oky softens oily slight ca mg 62Cardolite NC-104-20 Cashew Nut Shell Oil Friction Particles Smoky veryslight softening slight odor TABLE V Resole Resin Formulations Resin RawMaterial a b c d e f g h i j* Acetic Acid 0.18 0.04 Alcohol 28.90Ammoniacal Liquor 0.78 2.43 Aniline 4.86 Casein 1.66 Caustic Soda 0.150.38 03.6 0.17 2.14 Citric Acid 0.18 Deodorant 0.01 Formaldehyde (37.2%)47.36 54.41 g 49.44 50.74 48.44 29.00 56.91 45.09 24.45 Hexamethylenetetramine 1.18 Lime 0.71 0.81 Melamine (Buffered) 12.31 Meta-Para Cresol1.78 Methanol 1.65 Ortho Cresol 3.85 Oxalic Acid 0.24 0.02 Para-TertiaryButyl 21.60 Phenol Para-Tertiary Octyl Phenol 19.93 Phenol 43.22 38.8632.93 36.95 18.77 19.93 40.65 52.37 100.0 Phosphoric acid F 0.61 Proylene Oxide 121.5 Sul uric Acid 2.76 Triethylamine 7.2 Urea (Shotted)7.72 Urea Formaldehyde 23.84 Water 1.51 1.16 15.57 0.63 1.63 0.48

Xylene 'ln resole Rj; the phenol. formaldehyde and 2.5 purts n1trlethunolumine were first reacted. This product is then oxypropylatedwith the remaining specified ingredients.

TABLE VI Novolac Resin Fomiulations Resin Raw Material a b c d e i f g hAmmoniacal Liquor 2.31 Aniline 43.92 Beta Naphthol 37.80 Butyl AcidPhosphate 0.02 Castor Oil 36.77 Caustic Soda 0.01 Ethylene Oxide 36.68Formaldehyde (37.2%) 6.67 40.62 54.32 22.92 34.70 16.98 19.72 35.95Furfurul 3.30 lsobutyraldehydc 17.42 Limc 0.14 0.48 Limonenc 19.19Linseed Oil 24.26 Maleic Anhydride 0.02 Sodium alkyluryl sulfonate 0.010.06 0.01 0.1 p-Octyl Phenol 73.95 Oxalic Acid 0.17 0.03 0.74 0.53Stearic Acid 1.10 Sulphuric Acid 0.08 0.88 0.61 Water 0.67 0.59 0.880.28 0.96 1.06 Xylene 5.58 Phenol 22.16 58.45 54.91 45.85 60.68 24.67

We Cla alkylated hydroxy aromatic hydrocarbon aldehyde 1. A frictionparticle consisting essentially of the nonnovalac and a hydroxyulkylatedhydroxy aromatic catalyzed product of the reaction at about 225 to aboutdrocarbou ld h d l Y 9 degrees Fahrenheit of at least about porooht y 8.The friction particle of claim 1 wherein said parti- Wolght ofal'loh"hydroxyalkylawd hy aromatlc cle comprises the product of reactionof the said nondrocarbon aldehyde resole contammgsubstantrally nohydroxyalkyhted hydroxy aromatic hydrocarbonetherified aromatic hydroxylgroups with at least about aldehyde resole with a mixture f id h d 5 pby weight ota noh'hydl'oxyalkylated hydroxy 30 alkylated hydroxyaromatic hydrocarbon-aldehyde noaromatlc hydrocarboh'aldohydo I hovotacu the volac and an alkylated hydroxy aromatic hydrocarbonproduct issubstantially insoluble in acetone, mfuslble, aldehyde resole. and doesnot soften slightly under mechanical force at 9. A brake liningcomprising the cured product f a a temperature below abouttoo degteosFahrenhett and friction particle of claim 1 a resin binder and aninorhas substantially no cohesive or bonding strength. m m

2. The particle of claim 1 wherein the first said resole 0, A b k linincomprising the cured product of in the Pattie]e is h cohdenaatton Pt ofPhenot about 30 to 60 weight percent asbestos fiber, up to andfol'maldahyde m alkalme-mbdtumabout 40 weight percent of other inorganicfillers and The P a otalm whotem the Stud hydtox' abrasives, about 5 to15 weight percent of the friction yalkylatod resole the Particle 15 thehrdroxyalkylated particle of claim 1 and about 15 to 30 weight percentproduct of a phenol with an aldehyde in alkaline meof binder diuml u 11.The friction particle of claim 1 which comprises Thofrlotloh Partlole ofotalm 1 Whlch composes the reaction product of about 5 to about 40percent by the reaction Product of about 5 to about 40 Percent by weightof an hydroxyalkylated novolac and about 95 to Weight of an y y ylrosoleaud ut9it9. about 60 percent by weight of a mixture of a nonabout60 Percent by wetght of a mtxture of a hydroxyalkylated, non-alkylatcdresole and a nonhydroxyalkylated, non-alkylated resole and anonhydroxyalkylatedv alkyluted nov01ac y y ylated, alkylated novolac. r12. The friction particle of claim 1 which comprises ThetrlotlohPartlotos of chum 1 which Compttses the reaction product of about 5 toabout 40 percent by the roaotloh Product of about 5 to about 40 Percentby weight of an hydroxyalkylated novolac and about 95 to weight of anhydroxyalkylated resoleand about 95 to about 60 percent by weight f amixture f a u about 60 Percent y walght of a mlxture of ahydroxyalkylated, non-alkylated resole and a nonhydroxyalkylated,non-alkylated novolac and a nonh d lk d lk l d hydroxyalkylated,noh'atkylatoorosola- 13. The friction particle of claim 1 whichcomprises 6. The friction particle of claim 1 WhlCh comprises thereaction product of 70 to about 90 percent b the reaction Product ofabout 5 to about 50 Percent by weight of a non-hydroxyalkylated,alkylated resole and weight of a non-hydroxyalklylated, alkylatedresole, about 30 to about [0 percent b weight f a about 5 to about 30Percent y weight of hydroxyalkylated alkylated novolac. hydroxyalkytatodatkylated novolac, and about 25 to 14. A brake lining comprising thecured product of a ou 90 Per en y gh 0ft! ofl-hydroxyalkyluted. about 30to 60 weight percent asbestos fiber, up to non-alkylated reS0lel about40 weight percent of other inorganic fillers and Tha friction Pattlcloof chum l t P abrasives, about 5 to 15 weight percent of the frictionClo Comprises the Product of o of stud particle of claim 13, and about15 to 30 weight percent hydroxyalkyluted hydroxy aromatic hydrocarbonaldcf binder hydc resole with a mixture of said non-hydroxyl

1. A FRICTION PARTICLE CONSISTING ESSENTIALLY OF THE NONCATALYZEDPRODUCT OF THE REACTION AT ABOUT 225 TO ABOUT 400 DEGREES FAHREHEIT OFAT LEAST ABOUT 30 PERCENT BY WEIGHT OF A NON-HYDROXYALKYLATED HYDROXYAROMATIC HYDROCARBON ALDEHYDE RESOLE CONTAINING SUBSTANTIALLY NOETHERIFIED AROMATIC HYDROXYL GROUPS WITH AT LEAST ABOUT 5 PERCENT BYWEIGHT OF A NON-HYDROXYALKYLATED HYDROXY AROMATIC HYDROCARBONALDEHYDENOVOLAC UNTIL THE PRODUCT IS SUBSTANTIALLY INSOLUBLE IN ACETONE,INFUSIBLE, AND DOES NOT SOFTEN SLIGHTLY UNDER MECHANICAL FORCE AT ATEMPERATURE BELOW ABOUT 400 DEGREES FAHRENHEIT AND HAS SUBSTANTIALLY NOCOHESIVE OR BONDING STRENGTH.
 2. The particle of claim 1 wherein thefirst said resole in the particle is the condensation product of phenoland formaldehyde in an alkaline medium.
 3. The particle of claim 1wherein the said hydroxyalkylated resole in the particle is thehydroxyalkylated product of a phenol with an aldehyde in alkalinemedium.
 4. The friction particle of claim 1 which comprises the reactionproduct of about 5 to about 40 percent by weight of an hydroxylakylatedresole and about 95 to about 60 percent by weight of a mixture of anon-hydroxyalkylated, non-alkylated resole and a non-hydroxyalkylated,alkylated novolac.
 5. The friction particles of claim 1 which comprisesthe reaction product of about 5 to about 40 percent by weight of anhydroxyalkylated resole and about 95 to about 60 percent by weight of amixture of a non-hydroxyalkylated, non-alkylated novolac and anon-hydroxyalkylated, non-alkylated resole.
 6. The friction particle ofclaim 1 which comprises the reaction product of about 5 to about 50percent by weight of a non-hydroxyalklylated, alkylated resole, about 5to about 30 percent by weight of non-hydroxyalkylated, alkylatednovolac, and about 25 to about 90 percent by weight of anon-hydroxyalkylated, non-alkylated resole.
 7. The friction particle ofclaim 1 wherein said particle comprises the product of reaction of saidnon-hydroxyalkylated hydroxy aromatic hydrocarbon aldehyde resole with amixture of said non-hydroxy-alkylated hydroxy aromatic hydrocarbonaldehyde novalac and a hydroxy-alkylated hydroxy aromatic hydrocarbonaldehyde resole.
 8. The friction particle of claim 1 wherein saidparticle comprises the product of reaction of the saidnon-hydroxyalkylated hydroxy aromatic hydrocarbon-aldehyde resole with amixture of said non-hydroxy-alkylated hydroxy aromatichydrocarbon-aldehyde novolac and an alkylated hydroxy aromatichydrocarbon-aldehyde resole.
 9. A brake lining comprising the curedproduct of a friction particle of claim 1 a resin binder and aninorganic filler.
 10. A brake lining comprising the cured product ofabout 30 to 60 weight percent asbestos fiber, up to about 40 weightpercent of other inorganic fillers and abrasives, about 5 to 15 weightpercent of the friction particle of claim 1 and about 15 to 30 weightpercent of binder.
 11. The friction particle of claim 1 which comprisesthe reaction product of about 5 to about 40 percent by weight of anhydroxyalkylated novolac and about 95 to about 60 percent by weight of amixture of a non-hydroxyalkylated, non-alkylated resole and anon-hydroxyalkylated, alkylated novolac.
 12. The friction particle ofclaim 1 which comprises the reaction product of about 5 to about 40percent by weight of an hydroxyalkylated novolac and about 95 to about60 percent by weight of a mixture of a non-hydroxyalkylated,non-alkylated resole and a non-hydroxyalkylated, non-alkylated novolac.13. The friction particle of claim 1 which comprises the reactionproduct of 70 to about 90 percent by weight of a non-hydroxyalkylated,alkylated resole and about 30 to about 10 percent by weight of anon-hydroxyalkylated alkylated novolac.
 14. A brake lining comprisingthe cured product of about 30 to 60 weight percent asbestos fiber, up toabout 40 weight percent of other inorganic fillers and abrasives, about5 to 15 weight percent of the friction particle of claim 13, and about15 to 30 weight percent of binder.